Native C-reactive protein (CRP), a marker of inflammation that is a planar pentameric arrangement of five identical 23 kDa subunits, exhibits calcium-dependent binding to phosphorylcholine (PC) and has been demonstrated to interact with artificial PC bilayers, although a disturbance of the bilayer organization is required (Volanakis and Wirtz, Nature, 281:155-157 (1979)). In vivo, endothelial apoptotic processes culminate in exposure of phosphorylcholine groups on the membrane surface and capture of circulating native CRP (Kim et al. Ann NY Acad. Sci. 987:68-78 (2003)). Once bound to PC, the pentameric ring of the human CRP opens, resulting in dissociation of the subunits into monomeric (single subunit) forms (Wang and Sui, Biochem. Biophys. Res. Comm., 288:75-79 (2001)).
Total CRP levels have been shown in multiple prospective epidemiological studies to predict future cardiovascular disease, including myocardial infarction, stroke, peripheral arterial disease, sudden cardiac death and cardiovascular events in general (Ridker, Circulation, 107:363-369 (2003)).